Permutation vs Combination
Permutations vs. Combinations
Permutation (Order Matters): Picking and arranging items where position counts.
Example: From {A, B, C}, choosing 2 gives 6 arrangements: AB, BA, AC, CA, BC, CB.
Formula: \(P(n, r) = \frac{n!}{(n - r)!}\)
Combination (Order Doesn't Matter): Choosing a group where position does not count.
Example: From {A, B, C}, choosing 2 gives 3 groups: AB, AC, BC.
Formula: \(C(n, r) = \frac{n!}{r!(n - r)!}\)
Quick Memory Trick:
- Lock combination \(\rightarrow\) Order matters (it's actually a permutation).
- Fruit salad \(\rightarrow\) Order doesn't matter (apples + bananas = bananas + apples).
Permutations & Combinations Calculator
Permutations P(M, N)
-
Combinations C(M, N)
-